Operating instructions
24
10 - STARTUP
If Burner Pulsates During Ignition:
1. 
Turn off boiler power. Shut off gas supply to boiler.
2. 
Take burner assembly apart by removing combustion 
air blower and gas valve/venturi assembly from boiler. 
Visually inspect inside of burner. Look for debris (PVC 
shavings, etc.). Remove debris if present.
3. 
Reassemble burner assembly, turn gas supply and 
boiler power back on, relight boiler.
If Burner Continues To Pulsates Or Fails To Light:
1. 
Check for proper vent, intake pipe sizing, proper vent 
lengths and vent confi guration. Refer to “Installation 
And Operation” on page 5 and “Combustion Air/ Vent 
Requirements” on page 11.
2. 
Check for proper gas supply pressure and proper gas 
line sizing to boiler. Refer to “Check Gas Supply” on 
page 15.
3. 
Check for orifi ce in negative pressure hose at gas 
valve, and 2” air intake pipe upstream of gas valve.
4. 
Relight boiler.
5. 
If boiler still does not light, 
A.  Disconnect air inlet pipe. Allow boiler to start, verify 
boiler fi ring rate and combustion properties. 
B.  Disconnect inlet air pipe by removing PVC inlet 
air piping from coupler located on air inlet of gas 
valve/venturi assembly. 
C. Relight boiler.
6. 
Verify fi ring rate and combustion when boiler lights. 
Refer to “Adjustments And Checkout” on page 29. If air 
inlet piping was disconnected in step 4 (above), leave it 
disconnected and make fi rst adjustment. Reconnect air 
inlet piping, then verify combustion CO
2
, adjust again if 
necessary.
7. 
If burner pulsation continues or boiler fails to light after 
performing above procedures, please contact technical 
service for further assistance.










